Described herein is a system and a process for providing acetylene, preferably at a high purity level (e.g., comprising 100 parts per million (“ppm”), or 10 ppm, or 1 ppm, or 100 parts per billion (“ppb”), or 10 ppb, or 1 ppb or less of solvent), to a point of use. More specifically, described herein is a delivery system that provides a continuous flow of virtually solvent free (e.g., comprising 100 ppm or below of solvent) acetylene for use in semiconductor manufacturing.
Semiconductor manufacturers are using acetylene (C2H2) for certain applications such as, for example, hard (carbon-rich) mask coating processes. Acetylene is typically provided at a point of use in a cylinder that can be delivered to the manufacturer and then removed and refilled. Acetylene, however, presents many problems in handling and delivery. Acetylene is the most thermodynamically unstable common gas, is highly flammable, has a very wide explosive range (from 2% to 80% in air), and under pressure and certain conditions can decompose with explosive force. With regard to the latter, pure acetylene under pressure as low as 6 psig can violently decompose under certain conditions. Acetylene cylinders are designed to avoid the aforementioned problems with decomposition and flammability by providing a porous material that is saturated with acetone or another suitable solvent into which the acetylene is dissolved. The combination of the porous mass and solvent allows acetylene to be stored safely in cylinders at a pressure of about 250 psig. However, the acetone solvent can introduce up to 10% acetone vapor which can contaminate the manufacturing process, end product, or both.
Accordingly, there is a need in the art to provide a system and a process for the safe handling and delivery of acetylene to a point of use wherein the acetylene is delivered at a high purity level particularly for semiconductor manufacturing processes.